1. Field of the Invention
The invention relates to a cutter device, more particularly to a cutter device for a wood planing machine.
2. Description of the Related Art
Referring to FIG. 1, a conventional wood planing machine 10 is shown to include a machine base 11, left and right pairs of upright posts 12 extending upwardly from two mounting sides of the base 11, and a carriage assembly 13 movable along the upright posts 12. A cutter device 20 (see FIG. 2) is mounted on the carriage assembly 13. The carriage assembly 13 is movable relative to the base 11 so as to define a gap therebetween for passage of a workpiece 14 that is to be planed by the cutter device 20.
As illustrated in FIGS. 2 and 3, the cutter device 20 includes a cylindrical cutter seat 21, two elongate cutting blades 22, two elongate press members 23, and two releasable tightening units. The cylindrical cutting seat 21 has opposite end faces 210, and a cylindrical surface 212 between the end faces 210. Each of the end faces 210 has a coupling shaft 211 that extends co-axially therefrom for coupling with a motor (not shown). The cylindrical surface 212 is formed with a pair of axially extending cutter receiving grooves 24 that extend from one of the end faces 210 to the other one of the end faces 210. Each cutter receiving groove 24 is defined by a blade supporting wall 242, a fastener bearing wall 243 opposite to the blade supporting wall 242, and a groove bottom 241 interconnecting the blade supporting wall 242 and the fastener bearing wall 242. Each cutting blade 22 is disposed in the respective cutter receiving groove 24, and has a wall bearing side 224 that leans on the blade supporting wall 242, a force bearing side 225 opposite to the wall bearing side 224, a longitudinal base edge 222, and a longitudinal blade edge 221 that is opposite to the base edge 222 and that projects relative to the cylindrical surface 212 of the cutter seat 21. Each press member 23 is disposed in the respective cutter receiving groove 24 adjacent to the force bearing side 225 of the respective cutting blade 22. Each releasable tightening unit includes a plurality of tightening fasteners 231 that force the respective press member 23 away from the fastener bearing wall 243 to enable the press member 23 to press tightly the corresponding cutting blade 22 against the blade supporting wall 242.
Some disadvantages that result from the use of the aforesaid conventional wood planing machine 10 are as follows:
(i) It is noted that two biasing springs 26 are disposed in recesses 25 formed in the groove bottom 241 to support the base edge 222 such that the blade edge 221 of the cutting blade 22 projects relative to the cylindrical surface 212. As such, during replacement of the cutting blade 22,the blade edge 221 cannot be arranged with ease to project uniformly from the cylindrical surface 212 due to spring fatigue or unequal biasing forces of the springs 26, thereby inconveniencing the replacement operation. PA1 (ii) The fastener bearing wall 243 is inclined relative to the blade supporting wall 242 so as to define a narrow opening for access to the groove bottom 241 in order to prevent removal of the cutting blade 22 when the cutter seat 21 rotates. However, the fastener bearing wall 243 intersects with a reference plane 244, that is generally parallel to the blade supporting wall 242 and that passes through the axis of the cylindrical seat 21 and forms an acute angle of 15 degrees therewith. Accordingly, the cross sectional area of the cutter seat 21 is relatively small, thereby weakening an overall rigidity of the cutter seat 21.